Yes. If you have Ultimate Offering, you can use the effect during the opponent's battle phase. You can use it to do two Normal Summons, yes, you can perform a tribute summon if you wish.
What's in italics is answering your question. The rest is just other helpful information. Answer from yugioh-card.com: If Ultimate Offering is face-up, you can activate its effect multiple times in the same chain.When you activate Ultimate Offering's effect, you pay the 500 Life Points as a cost at activation, and then the Summon occurs at resolution of Ultimate Offering's effect in that chain. This means that it is possible to Summon a monster in the middle of a chain with Ultimate Offering's effect.If you are using Ultimate Offering's effect to perform a Tribute Summon, you Tribute the monster when Ultimate Offering's effect RESOLVES and you perform the Tribute Summon, NOT when you activate Ultimate Offering's effect and pay the 500 Life Points.If your opponent activates a Trap Card, you can chain the effect of your face-up Ultimate Offering to the Trap Card to Tribute Summon Jinzo (if you had a monster on the field to Tribute) and negate the Trap Card's effect.You cannot flip Ultimate Offering face-up AND use its effect in the same chain; you must have Ultimate Offering face-up on the field before the current chain began.If you activate Ultimate Offering's effect to Summon, and your opponent chains Mystical Space Typhoon to destroy Ultimate Offering, the Summon does not resolve because Ultimate Offering is a Continuous Trap Card and is no longer on the field.You can activate the effect of a face-up "Ultimate Offering" during your Main Phase even if you have not done a Normal Summon yet this turn.
It requires 1 tribute
2011
A tribute summon is a form of Normal Summon. So that means you can only tribute summon OR normal summon ONCE per turn.
You can, only if something specifically says you can. Tribute for most Ritual Spell Cards can come from hand. But if the card doesn't specify, the tribute must come from your side of the field.
What's in italics is answering your question. The rest is just other helpful information. Answer from yugioh-card.com: If Ultimate Offering is face-up, you can activate its effect multiple times in the same chain.When you activate Ultimate Offering's effect, you pay the 500 Life Points as a cost at activation, and then the Summon occurs at resolution of Ultimate Offering's effect in that chain. This means that it is possible to Summon a monster in the middle of a chain with Ultimate Offering's effect.If you are using Ultimate Offering's effect to perform a Tribute Summon, you Tribute the monster when Ultimate Offering's effect RESOLVES and you perform the Tribute Summon, NOT when you activate Ultimate Offering's effect and pay the 500 Life Points.If your opponent activates a Trap Card, you can chain the effect of your face-up Ultimate Offering to the Trap Card to Tribute Summon Jinzo (if you had a monster on the field to Tribute) and negate the Trap Card's effect.You cannot flip Ultimate Offering face-up AND use its effect in the same chain; you must have Ultimate Offering face-up on the field before the current chain began.If you activate Ultimate Offering's effect to Summon, and your opponent chains Mystical Space Typhoon to destroy Ultimate Offering, the Summon does not resolve because Ultimate Offering is a Continuous Trap Card and is no longer on the field.You can activate the effect of a face-up "Ultimate Offering" during your Main Phase even if you have not done a Normal Summon yet this turn.
It requires 1 tribute
ya
duel
contend
havoc
activate
2011
defeat all level 1 opponents 5 times each
puzzle
force
Battle